On Tue, 2015-07-14 at 12:52 +0200, Dario Faggioli wrote:
> On Tue, 2015-07-14 at 10:37 +0100, Ian Campbell wrote:
> > On Tue, 2015-07-14 at 11:25 +0200, Dario Faggioli wrote:

> > > > http://logs.test-lab.xenproject.org/osstest/results/host/merlot0.html
> > > > http://logs.test-lab.xenproject.org/osstest/results/host/merlot1.html
> > > > 
> > > Can I ask why (I mean, e.g., comparing what with what) you're saying it
> > > seems to have helped?
> > 
> > There seemed (unscientifically) to be fewer of the libvirt related
> > guest-start failures.
> > 

> Old timeout, failing:
> http://logs.test-lab.xenproject.org/osstest/logs/59105/test-amd64-amd64-libvirt-xsm/info.html
> 
> New timeout, success:
> http://logs.test-lab.xenproject.org/osstest/logs/59311/test-amd64-amd64-libvirt/info.html
> 
> And, looking at how long QEMU did take to start up that would be:
> 
>   13:44:32 - 13:43:42
> 
> i.e., just a bit less than 1min!
> 
> So, yes, it looks that this change is actually going to help in this
> case.
> 
> What I'm missing is how it is possible that, on an idle system, DM
> spawning takes that long. As said, in Anthony's OpenStack case, the
> system was quite busy... not that it can't be a bug (somewhere, perhaps
> in Linux) in that case too, but here, it looks even more weird to me.
> 
> May it be the NUMA misconfiguration? Well, if yes, I'm not sure how...
> 
BTW, Ian, perhaps it's not that urgent, but how cumbersome would it be
to setup a few ad-hoc flights, like you did here:

 http://logs.test-lab.xenproject.org/osstest/logs/58853/

when also doing what Anthony was doing for stracing QEMU, as he
described in here:

 http://bugs.xenproject.org/xen/mid/%3C20150624133948.GJ3393@perard.uk.xensource.com%3E

I'm not sure what we could find, nor whether we should expect the strace
to be similar to Anthony's. Perhaps not, as the system here is idle, and
perhaps something would highlight or hint at where to look in this
specific case... Or maybe none of the above, but it may be worth a try.

If there is anything I can do for helping setting this up, just let me
know (here or on IRC).

Regards,
Dario
-- 
<<This happens because I choose it to happen!>> (Raistlin Majere)
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Dario Faggioli, Ph.D, http://about.me/dario.faggioli
Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)